Lichtenberg figures are fractal patterns left behind when a high-voltage surge breaks down a solid or liquid dielectric. In electrical engineering, finding these carbonized tracks on insulators, bushings, or switchgear barriers is a clear sign of severe partial discharge or a previous flashover. They permanently degrade the insulation's dielectric strength.
Pull that standoff insulator out of service; it has a massive Lichtenberg figure tracking right down to the grounded chassis.
Once a Lichtenberg figure forms on an insulator, the creepage distance is compromised and a dead short is inevitable if the component is not replaced.
Also heard as
- electrical treeing
Related terms
Tracking
Conductive carbon trail that leakage arcs through dirt and moisture gradually burn across an insulating surface.
Partial discharge
Tiny discharge in a void, on a surface or at a sharp edge that never spans the whole insulation, an early sign of decay.
Flashover
Disruptive discharge over or around insulation that creates a short circuit through the air.
Insulation
A material with high electrical resistance used to isolate conductors and prevent current leakage.